Opportunity has been moving toward a candidate patch of rock outcrop in preparation for a rest of the mobility system over the coming holiday. There continues to be concern with the elevated motor currents seen in the right front wheel.

On Sol 1920 (June 18, 2009), Opportunity drove backwards about 63 meters (207 feet) south. The right front wheel currents were elevated but were not divergently increasing. After a few sols, Opportunity drove another 7 meters (23 feet) to a nearby outcrop.

Robotic arm activities on surface targets with the microscopic image (MI) and the alpha particle X-ray spectrometer (APXS) were performed on Sols 1924 and 1925 (June 22 and 23, 2009).

Further drives are planned to reach a large region of rock outcrop. Also, the week saw further implementation of the miniature thermal emission spectrometer (Mini-TES) mirror dust mitigation. The Mini-TES shroud is left open overnight to see if the environment will clean the elevation mirror.

As of Sol 1924 (June 22, 2009), the solar array energy production was 450 watt-hours with an atmospheric opacity (tau) of 0.480 and a dust factor of 0.530, indicating that 53 percent of sunlight hitting the solar array penetrates the layer of accumulated dust on the array. As of Sol 1926 (June 24, 2009), Opportunity’s total odometry remains at 16,639.71 meters (10.3 miles)

Spirit is continuing her ambitious remote sensing and in-situ (contact) science observations at the location called "Troy" on the west side of Home Plate.

Using the rover robotic arm (instrument deployment device, IDD), the rover has been exploring a set of surface targets that hold clues to the past geologic history at this location.

On Sol 1941 (June 18, 2009), a Microscopic Imager (MI) stack of images was collected on target Penina3, then the Alpha Particle X-ray Spectrometer (APXS) was placed for an overnight integration. On the next sol, the Moessbauer Spectrometer (MB) was placed on a different target for a multi-sol integration. The next few sols included some late-day activities where the rover imaged the Earth and Venus in the night sky.

On Sols 1945 and 1946 (June 22 and 23, 2009), Spirit investigated another set of surface targets, again with MI stacks and APXS overnight integrations. On Sol 1946 (June 23, 2009), another solar array dust cleaning event occurred, increasing the available energy each sol even more.

At JPL, a special test form has been installed for ground testing with the surface system testbed (SSTB) rover to guide the eventual extraction activities on Mars for Spirit. The materials for the soil simulant to be used in the test form have been delivered and are in the process of being formulated and mixed. As of Sol 1947 (June 24, 2009), solar array energy production increased to 945 watt-hours with atmospheric opacity (tau) of 0.480 and an improved dust factor of 0.834. Total odometry remains at 7,729.93 meters (4.80 miles).

Opportunity has been stationary this week resting the right-front drive actuator. During this time, the rover is conducting a series of robotic arm (IDD) activities.

On Sol 1913 (June 11, 2009), the rover collected a set of microscopic imager (MI) sky flats to calibrate the camera images. Opportunity also began a mitigation effort for apparent dust on the elevation mirror of its miniature thermal emission spectrometer (Mini-TES). The mirror shroud will be left open to the environment overnight to allow the wind to clean some of the dust off.

On Sol 1915 (June 13, 2009), a Mars seismometry experiment was conducted using the rover's accelerometers. On Sol 1918 (June 16, 2009), Opportunity used the MI to collect images of target "Ios" before placing the alpha particle X-ray spectrometer (APXS) for an overnight integration.

As of Sol 1919 (June 17, 2009), Opportunity's solar array energy production is 416 watt-hours. Atmospheric opacity (tau) is 0.466. The dust factor is 0.524, indicating that 52.4 percent of sunlight hitting the solar array penetrates the layer of accumulated dust on the array. Opportunity's total odometry remains at 16,569.05 meters (10.3 miles).

Spirit remains stationary on the west side of Home Plate in the location called "Troy". The rover continues to be busy with an ambitious observation campaign employing both remote sensing and in-situ (contact) science with the robotic arm (instrument deployment device, IDD).

The soil disturbed by the rover's embedding has been the subject of extensive science investigation. Five out of the past seven sols have involved using the instruments on the end of the robotic arm to collect images and composition spectra of five distinct targets. Images from the panoramic camera (Pancam) and spectra from the miniature thermal emission spectrometer (Mini-TES) have also been collected. Extensive nighttime observations have been planned to make use of the abundant energy the rover has right now.

At JPL, preparations are continuing for ground testing with the surface system testbed (SSTB) rover. A special test form has been constructed to hold the new soil simulant that will recreate Spirit's martian terrain. The new simulant has been validated with single-wheel "shoebox" testing by the SSTB rover. Large quantities of simulant ingredients have been ordered and are expected within days.

As of Sol 1939 (June 17, 2009), Spirit's solar array energy production is at 853 watt-hours, with atmospheric opacity (tau) of 0.486 and a dust factor of 0.760. Total odometry remains at 7,729.93 meters (4.80 miles).

Opportunity continues to drive south on the way to Endeavour crater. On Sol 1906 (June 4, 2009), the rover completed a 69-meter (266-foot) drive due south. Elevated actuator currents with the right-front wheel continue to cause concern. The rover rested for four sols before driving again, conducting observations with the panoramic camera (Pancam) and atmospheric argon measurements with the alpha particle X-ray spectrometer (APXS).

On Sol 1910 (June 8, 2009), the planned drive stopped early because a multi-wheel current limit threshold was exceeded. A diagnostic maneuver on the next sol was successful indicating the cause on the previous sol was due to the elevated right-front wheel motor currents. A long, backward drive was performed on Sol 1912 (June 10, 2009). Driving backwards is one technique to mitigate the elevated wheel currents. However, wheel currents continued to be elevated after that 72-meter (236-foot) drive. Further resting of the rover's actuators is being considered.

The plan ahead includes opening the shroud of the miniature thermal emission spectrometer (Mini-TES) to expose the instrument's dust-contaminated elevation mirror to the environment. This is an attempt to allow the wind environment to clean dust off the mirror.

As of Sol 1912 (June 10, 2009), Opportunity's solar array energy production is 431 watt-hours. Atmospheric opacity (tau) is 0.589. The dust factor is 0.549, indicating that 54.9 percent of sunlight hitting the solar array penetrates the layer of accumulated dust on the array. Opportunity's total odometry is 16,569.05 meters (10.3 miles).

Spirit remains stationary on the west side of Home Plate. Work continues on developing the ground testing to assist the rover in extracting itself from the embedding in this location, called "Troy".

The rover has been busy with an ambitious observation campaign employing both remote sensing and in-situ (contact) science with the robotic arm (instrument deployment device, IDD). The soil, disturbed by the rover embedding, reveals unconsolidated, light-toned material. Analysis indicates this material consists of differing amounts of ferric sulfate, calcium sulfate, silica and other constituents.

On Sol 1927 (June 4, 2009), the IDD used the microscopic imager (MI) to collect a stack of stereo images, then placed the alpha particle X-ray spectrometer (APXS) for an overnight integration. On the next sol, the APXS was moved to a different surface target for a second integration. On Sol 1929 (June 6, 2009), another set of MI images was collected and the Moessbauer (MB) spectrometer was placed for a multi-sol integration.

On Sol 1933 (June 10, 2009), a full-rotation test was performed on the left-middle wheel to explore a stall event from Sol 1899 (May 6, 2009). The test successfully rotated the wheel one full rotation backwards and more than one full rotation forward past the point of the original stall. The wheel moved freely with no re-occurrence of a stall.

Preparation for ground testing of embedding extraction techniques continues. A soil simulant has been established by way of a series of "shoebox" (single wheel) tests of candidate materials with the surface system testbed (SSTB) rover in the sandbox at JPL. A test form to contain rover-scale quantities of soil simulant is under construction.

As of Sol 1932 (June 9, 2009), Spirit's solar array energy production is at 828 watt-hours, with atmospheric opacity (tau) of 0.502 and a dust factor of 0.749. Total odometry remains at 7,729.93 meters (4.80 miles).

Although Spirit has yet to begin to extricate herself from the loose, soft terrain on the west side of Home Plate, the rover has been active using her instruments to assess her embedded state.

This week the robotic arm (Instrument Deployment Device, IDD) with the Microscopic Imager (MI) were used to take a mosaic of images of the rover's underbelly. The MI, a short focus camera, was never designed to take these types of long-focus images. This technique was first tested by Opportunity and the test demonstrated that although the images will not be sharply focused, sufficient detail can be seen.

Spirit's first MI mosaic of the underbelly was collected on Sol 1922 (May 30, 2009). The IDD then positioned the MI to collect a stack of images of a science soil target and placed the Moessbauer (MB) spectrometer on the science target for a multi-sol integration. Spirit collected a second underbelly image mosaic on Sol 1925 (June 2, 2009). This time the IDD extended further under the rover to capture more detail. The IDD then collected another MI stack of images of a science target followed by the placement of the Alpha-Particle X-ray Spectrometer (APXS) on the same target. Frames of a 360-degree color panorama, called the Calypso panorama, were collected. Targeted observations were made with the miniature thermal emission spectrometer.

The project was successful in restoring files to a computer server so that the surface system testbed (SSTB) rover at JPL could be operated. Soil simulant tests with the SSTB were performed on "Bag House" dust simulant. Unfortunately, the test results show that the Bag House dust is not suitable as a simulant for Spirit's situation. A new simulant is being formulated and will be tested shortly.

As of Sol 1926, solar array energy production was generous at 884 watt-hours with atmospheric opacity (tau) of 0.458 and a dust factor of 0.772. Spirit's total odometry remains at 7,729.93 meters (4.80 miles).

Opportunity has been busy driving south. The rover drove four out of the last six sols. The drives have all been blind drives with regular slip checks for progress.

On Sols 1900, 1902 and 1904 (May 29, May 31 and June 2, 2009), Opportunity drove 66, 71 and 74 meters, (217, 233 and 243 feet), respectively. On Sol 1905 (June 3, 2009), the rover only accomplished about 30 meters (98 feet) of driving before the time ran out. Activities were very time-constrained on that sol.

Motor currents in the right-front wheel continue to be elevated. Limiting the drive distance and employing regular, short, backward slip checks seems to mitigate further increases in right-front wheel current.

As of Sol 1905 (June 3, 2009), Opportunity's solar array energy production is 413 watt-hours. Atmospheric opacity (tau) is 0.559. The dust factor is 0.542, meaning that 54.2 percent of sunlight hitting the solar array penetrates the layer of accumulated dust on the array. Opportunity's total odometry is 16,424.22 meters (10.2 miles).